Why You Don’t Want Mastic In Your Tile Shower Unless You Want Tile Repair Bills!

November 7th, 2009 by Grout Guy

Here at Boston Grout we get the same situation happen almost every week – someone’s tile shower is falling apart and needs repair. The other day we were at a nice home in Newton (that’s a nice suburb of Boston, for those who might not know the area). The reason we were there was to regrout and caulk the shower. The lady of the house literally pulled a tile off the shower wall with her bare hands and said: Is the tile supposed to come off that easily?

How should we answer?

Something on the order of “NO, NO, NO!!!!!!!!!!!!!!!!”

Bear in mind, this is in very nice house easily worth millions in a very nice neighborhood and they had recently finished a $60,000 renovation. Maybe the contractor would use premium materials, just maybe?? Maybe he’d hire a tilesetter who knows what to use and what not to use? Just maybe?

It gets us mad when tilesetters who are supposed to know their trade use a material that creates this sort of problem. It’s the same material, time after time. It should be outlawed, in my opinion, or at least have huge warning labels all over the bucket.

What is this nasty, shower-destroying, money burning, evil stuff called?

Mastic. It also uses the alias ‘pre-mixed thinset’.

What’s so bad about it?

Simple. It’s not real cement – it has more in common with glue. And it’s water sensitive. Meaning that over time when water seeps through the grout lines, the mastic gets weaker and weaker and the bond between the tile and wall gets looser and looser. At some point, you can actually have tile fall off the wall or pull them off yourself using your hand. Make no mistake, water always get through grout lines.

This is true even if the tiler used real cement board walls. Glue just can’t handle the amount of moisture that showers create. If it’s a steam shower, it’s doubtful the shower might even last a few months of normal use.

How can you recognize this evil compound? Simple: it comes all premixed up for your convenience in a tub or bucket and you just scoop some out and smear it on the wall. If you are hiring a tile contractor to retile a shower and he hauls out a bucket of stuff to stick the tile on, and it’s all ready to use instantly, it’s mastic. What he should be using is real thinset cement, which is always a powder in a bag that he has to mix with water first before it’s usable.

Can a mastic shower be saved if tile are coming off the wall? It depends. If you have more of the original tile, we might be able to replace some of the broken or cracked ones, or maybe even scrape off the back and re-use some if that’s feasible. Tile repair is tricky and takes more skill than original installation, so we do charge extra. When we finish a repair, we almost always regrout the shower so the new grout on the repair won’t ‘stand out like a sore thumb.’ The repair part of the job might be under a hundred dollars if it’s a few tiles, or it can and has run over a thousand dollars for more extensive repairs. What a waste for the homeowner because the tile setter was too lazy to use the right thinset cement and used mastic instead!

We’ll do a post on why mastic is used and where it’s OK to use it, maybe later next week. Meantime, if you’re having tile installation or a tile shower built, just call the builder or tile guy and insist that he or she brings no mastic in your house. You’ll be better off and hopefully a mastic manufacturer will go out of business.

If you live in any of the towns listed below, and you suspect you’re a victim of mastic tile work, and you need either tile repair or regrouting, give us a call at 617-500-9271 or fill out this form below and we’ll get right back to you with an instant quote and any help we can offer. I should note that our repairs are done the way mechanics work: since most of the important issues are hidden, we work by the hour to fix them. Meaning we can’t always know the final bill before we start, but we can estimate it based on other similar repairs we’ve done.

Towns where Boston Grout does tile repair: Boston, Brookline, Milton, Wellesley, Newton, Weston, Wayland, Dover, Concord, Acton, Lincoln, Lexington, Bedford, Westford, Cambridge, Somerville, Arlington, Winchester, Belmont, Woburn, Waltham, Ashland, Framingham, Sherborn, Holliston, Hopkinton, Medway, Millis, Norfolk, Walpole, Norwood, Westwood, Sharon, Stoneham, Foxborough, Foxboro, Canton, Stoughton, Needham, Ashland, Chestnut Hill, Natick, Sudbury, Maynard, Stow, Watertown, Dedham, West Roxbury, Roslindale, Jamaica Plain, Randolph, Weymouth, Cohasset, Scituate, Braintree, Holbrook, Quincy, Rockland, Hanover, Hingham, Medway, Franklin, Wrentham, Medford, Malden, Everett, Revere, Charlestown, Winthrop, Chelsea, Melrose, Saugus, Peabody, Marblehead, Ipswich, Swampscott, Lynn, Wakefield, Tewksbury, Woburn, Burlington, Reading, Lynnfield, Wilmington, Middleton, Wenham, Hamilton, Essex, Manchester, Gloucester, Topsfield, Boxford, Boxborough, Boxboro, Rowley, Georgetown, Andover, North Andover, Haverhill, Carlisle, Billerica, Ayer, Harvard, Lawrence, Methuen, Salem, Beverly, Salisbury, Amesbury, Newbury, Newburyport, Harvard, Lancaster, Bolton, Franklin, Mendon, Newtonville, Hopedale and Milford.